Joint for leg supports and artificial limbs in general



ERAL

1945- i M. MEIER I -IQFER JOINTS FOR LEG SUPPORTS AND ARTIFICIAL L IMBSIN GEN Filed Dec. 6, 1943 Patented July 3, 1945 JOINT FOR LEGsUPPoRr-sANnfAn'rIFioiAn p v f Max Meierhofer, Erlenbach', urich,

. Switzerland 1.

. Application December 6, 1943,

erial No. 513,110. g

In Switzerland September-$1 1 Claim. (01. 2874101 v;

This invention relates to joints for'leg sup ports and artificial limbsin general.

In the joint forleg supports and artificial limbs in general, accordingto the present invention, in one of two joint parts, that areinterconnected tation between the parts 2 and 4. This range by pivotmeans at mutually overlapping portions I said arts, a, stop means isprovided which is fitende to cooperate with the other Jo nt part forlimiting the angular range of relative rotational movement between saidparts, the clearance formed by effectof this angular range being coveredby a cover plate secured to one of said parts.

This arrangement serves the purpose of preventing a garment pulled overthe jo nt, for example a stocking, from being caught in the Jomt andthus damaged or torn,

A well known drawback of the conventional open gap joints in legsupports and artificial limbs in general consists in that garments ofthe wearer easily tangle with this joint so as to get caught therein andare thus liable to be damaged.

The joint forming the object of the present invention is illustrated inthe accompanying drawing, by way of example only, in the form of a legsupport for use by a lame person, in wh1ch Fig. 1 shows a side elevationof the lower part of the leg support; I

Fig. 2 is a similar elevational view of the lower part of the legsupportan a larger scale;

Fig. 3 is a view as seen at right angles to that showninFig.2;

Fig. 4 is a sectional view corresponding to- Fig. 5 is a view similar tothat shown in Fig. 2 partly in section;

Fig. 6 shows a side elevation of a modified cover plate;

Fig. 7 is a view as seen at right angles to that shown in Fig.6; v I

Fig. 8 is a sectional view corresponding to Fig. 7, and

Fig. 9 shows a cross section on the inFig. 6. o

Referring to Fig. 1 of the drawing, the numeral l designates the footportion of the support and 2 refers to the ankle portion upstanding fromthe foot portion. To the ankle portion 2 a shank rail line IX-IX '4 ispivotally connected by means of a tap bolt 3, to the upper portion ofwhich rail in turn a thigh rail (not shown) is pivoted. The lower endportion of the shank rail 4 is provided with two symmetrical oblique endfaces 5 which are directed towards the center of the tap bolt 3 insymmetrical relation to each other and which by cooperation tatntwb'respectiveoblique faces 6 ,on a stop plate .1 immovably connectedhto theankle portion 2. define the-angularrange. of relative roamounts in thepresent instance, for example, to about 30.

The stop plate 1 is immovably secured to the part 2 by means ofacountersunk rivet 8 andtwo countersunk pins 9. The connecting rivet 8and the bolt 3 serve for securing in position a cover plate ID. Thisplate is exteriorly disposed at the point of junction of the parts 2 and4 and bridges the gap existing between the oblique faces 5 and 6 bywhich means appropriate protection against the stocking pulled over thesupport being caught in thisgap is provided. The parts I, 2, 4 and I0consist of a light metal, advantageously anticorplate In is coveredtowards the'outsid odal, which may be provided with a layer ofnitrocellulose varnish or enamel as a coating against the corrodingeffect of perspiration.

0n the tap bolt 3 connecting the joint parts 2, 4 with each other a bushI2 is carried which is advantageously made of graphite bronze or fibre.On the ends of the bush l2 for receiving the shank rail 4bearing discsl3 made of thin sheet steel are placed and inserted in lateral recessesin the shank rail 4. of friction between the side surfaces of the parts2, 4 and I0 can be reduced to such an extent as to be practicallynegligible and no lubrication need be provided for the joint in whichway soiling of the stocking, which hitherto had been unavoidable due tothe necessity of periodically lubrieating the joint with oil, is doneaway with.

The arrangement shown in Figs. 6 to '9 differs from that precedinglydescribed merely by a modified configuration of the cover plate Ill. Thelatter is provided-on a portion of its circumference with aperpendicularly bent'off rim M which is directed towards the joint part2 .and bears against the same. on the cover plate Ill extendsapproximately throughout the range beginning at one of the oblique faces6 on the immovable stop plate I downwardly and around to the otheroblique face 6 of the latter so that within this range the clearance gapbetween the stop plate land the cover The upper end of the cover plateI0 is semi-acircular.

The individual knee joints of the support are constructed similarly tothe ankle joint described and they obviously have a correspondingangular range, approximating for example which extends between the shankrail and the thigh rail. In Fig. 1 the cover plate ID for the y th smeans the setting up This projecting rim l4 knee joint is shown, whichplate is fastened to the lower end of the thigh rail by two rivets (notshown) that are countersunk on both sides like the rivet 8.

The joint structure according to this invention makes possible thwearing of silk stockings on leg supports actually only from now on,whilst the supports are rendered so to speak invisible, which is highlyimportant insofar as it is a fact that bodily disabled persons make aneffort to disguise their abnormalities as much as possible. Further thejoint structure according oting means extends, a lubricating bushing extending around said pivoting means within the opening of the said otherjoint portion, a spacer to the invention requires relatively littlespace in the direction of the pivot axis of the joint and themanufacture of the support is feasible by means of light metal materialavailable on the home market. in conjunction with the fact that forgingand chromium-plating can be dispensed with. At the same time the weightof the structure can b kept down, which is generally highly appreciatedby the wearers, for example persons disabled in a leg. p

The joint structure according to the invention This facilitates themanufacture;

plate fixedly secured to the first joint portion adjacent the end of theother joint portion, said spacer plate and the connection portion ofsaid other joint portion having abutment means facing in both directionsof turning around said pivot for limiting the movement of the joint, anda cover plate secured on said spacing plate and extending over theintermovable portions of the spacing plate and adjacent connectionportion of the other joint member .to prevent entanglement of garmentsorthe like in the joint.

MAX MEIERHOFER.

